1. Field of the Invention
The present invention relates to a pixel and an organic light emitting display device using the same.
2. Discussion of Related Art
Recently, various flat panel display devices with reduced weight and volume in comparison to a cathode ray tube display device have been developed. The flat panel display devices include a liquid crystal display (LCD) device, a field emission display (FED) device, a plasma display panel (PDP), an organic light emitting display device, etc.
An organic light emitting display device displays an image by using organic light emitting diodes (OLEDs) to generate light by the recombination of electrons and holes. The organic light emitting display device has a fast response speed and a low power consumption.
The organic light emitting display device controls the amount of current flowing to the organic light emitting diode by using driving transistors, which are included in each pixel to express a gray level. Typical organic light emitting display devices suffer from a problem of displaying an image with non-uniform luminance due to variations in threshold voltage and mobility of the driving transistors.
In order to overcome the foregoing problem, a method capable of compensating for the threshold voltage and the mobility of the driving transistor by changing an electric potential of a power supply, which supplies a current to the organic light emitting diode, into a first electric potential (high electric potential) or a second electric potential (low electric potential) has been suggested. (Korea Patent Publication 10-2007-0112714)
However, in order to change the electric potential of the power supply, extra circuit components are required (e.g., a filter etc.), and the power supply may require a heat sink due to the generation of high heat.